Question

when the rivers are slow​

Answer 1

Generally a narrower, more circular river channel allows faster flow of water. Broader flat channels tend to slow a river down. 2. Smoother channels also allow faster flow of water; rougher channels slow water flow.

Answer 2

Explanation:

When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep.